Filter/dryer location important?

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Old 03-25-03, 07:42 AM
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Filter/dryer location important?

I just got central installed in my house yesterday. In going over the work with the installer, I noticed and asked about a bulge in the smaller copper line just before the TXV, several inches from the coil he installed above my furnace. He informed me that was a filter, and then sheepishly stated that it's normally installed close to the condenser, but he didn't realize his mistake until it was too late. He said it'd be just fine where it is, but I thought I'd ask you guys to see if he's shooting straight with me. Should I be concerned about the filter being on the wrong end of the copper line? Also, are these filters typically bi-directional? I'm wondering if it's possible the filter is installed backwards in addition to being on the wrong end. If this is a concern too, is there a way for an HVAC novice to tell?

While I'm bugging you guys, can I get a price check? I paid about $3150 here in the Denver area for a 3.5-ton, 13 SEER, R-22, Lennox Elite 13 condenser with a 4-ton coil, including tax & permits. The copper lines had to run about 15 feet inside a finished basement ceiling. This was a new install, so electrical work cost an additional $350 (long run up through attic and down the other side of the house), which will be offset by a $350 rebate from the local utility company for getting a 13+ SEER unit. The sales guy made it sound like this was a sale price. So was my price really good, or just my sales man?
 
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Old 03-25-03, 10:03 AM
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new AC

First I would ask why did he put a filter drier on this new set up?If he had used a vacuum pump for dehydration of the refrigeration system like he should have
Yes the filters should show you on them how the flow should go.The only one I know of that will go both ways for the flow is a heat pump filter drier. It can be there by the coil but why he put It there I dont know.
Now as for cost. Im not there, I didnt see the job and Its hard when you dont know the what why and how of job costs where you are. You could have got a higher Seer unit but for the amount of time you will run the AC there it was not worth it , so you did good there ED
 
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Old 03-25-03, 11:36 AM
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Ed, the installer told me he used a vacuum pump 3 times. I was present for one of the runs. I guess he was just playing it safe with the filter drier? At any rate, I took a quick dash home for a bite to eat and to check on the filter. After much squinting in my dark furnace room, I was able to see arrows pointing towards the coil. Thanks for the reassurance. I can rest easier now.
 
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Old 03-25-03, 06:10 PM
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Actually, in cooling mode, the filter is OK being near the coil. Its purpose is to trap contaminants or moisture before it gets to the TXv and compressor. If it was near the unit, there would be X number of feet of liquid line that could have contained contaminants. If the tech pulled the system to 1000 microns, you could have done without the filter but I see the wholesalers many times including them on new systems. I think they are just trying to pump up the total sale. On a heat pump it also makes it more difficult when you need to calculate the total system charge.

I am located in NE Pa and I think the price of the work was acceptable.
 
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Old 03-25-03, 07:57 PM
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Thanks KField. So my installer's "mistake" actually was to my benefit? That's nice. It sounds like I got a fair price, but hardly the deal I was led to believe. Oh well.
 
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Old 03-25-03, 08:29 PM
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Talking Residential vs Commercial

In commercial HVAC/R there is no system that does not get a filter/drier and for low temp (freezer) work a suction filter/drier is also the norm.
Not as critical for a/c but a f/d installed on the system will gather up contaminants throughout the equipments life.
Ten years down the road when the condenser fan motor craps out and it takes a week of running before you figure out what's going on, the f/d will eat up the contaminants the compressor spits into the system.
 
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Old 03-27-03, 05:38 AM
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filter location

i agree with the advice you have gotten here. if i were to change just the coil, i would install the filter drier before the metering device. price sounds fair for atlanta market.
 
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Old 03-27-03, 10:55 AM
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Thanks everyone for your replies!
 
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Old 03-27-03, 07:50 PM
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Talking Old School

Sounds like this tech has been around a few years. Triple evacuation was a practice used a few years back when people had time, and would break the vacuum to absorb a small amount of moisture or air, using the freon, and pull a vacuum again. This was a reliable practice but expensive. It was mainly for refrigeration more than AC (high temp). In all actuality... the liquid line filter dryer is suppose to be just before the metering device, BUT, most guys try keeping it outdoors for convience sake with the sight glass, this way the customer doesn't even have to be home to fix most things....in a pinch, sometimes. One problem is that most units come equipped with a dryer already in the condensing unit....although just a pencil dryer...
 
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Old 03-27-03, 08:01 PM
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Exclamation Triple evacuation

Triple evacuation not only is "old school", but is strictly forbidden where environmental regs against intentional release are in place.
It was an effective enhancement to evacuation, but in cases where a micron guage was not used, you could never be sure when a deep vacuum was obtained, which would make the triple evacuation useless.
 
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Old 03-27-03, 08:30 PM
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Talking triple evac

This practice isn't forbidden!!! Venting is! It just requires recovering the vapor. I,ve seen in refrigeration systems where you can get to 5-7 hundred microns and still have water in the system...The vacuum lowers the boiling point of water but unless it's there a real long time, has real warm temperatures, or artifically heated, moisture can still remain. This was just one of many tools the tech had. Nitrogen, is inert, but will also absorb moisture in a system. A good tech will use a vacuum gauge, most don't, especially with high temp...I'm the only one I know that even has a vacuum analyizer....actually two!
 
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Old 03-28-03, 04:53 AM
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I'm glad to see that you have the proper equipment.

Your original reference to "old school" had made mention of using refrigerant to break the vacuum, which was how this method of evacuation was originally taught.
In our environmentally conscious world, this method is no longer permitted.
 
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Old 03-28-03, 02:09 PM
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stupid question here

i too am from the old school, i remember how we used to vent freely, and never worried about it. triple evac was the rule, but in this day, why can we not break the vacuum with refrigerant then recover it then vac again? too many techs do not use a vacuum pump anymore, and in my opinion this severly shortens the life of the unit. this is where the statement "proper installation often is more important than the brand name."
 
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Old 03-29-03, 07:46 AM
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Cool Recovery

I remember being told that Sears actually confiscated their vacuum pumps and tried to blow refrigerant through / purge, to speed things along to save money,.... as a result multiple compressor failures were poping up and cost them dearly...
At present, I don't know anyone out there without a vacuum pump. Most put the pump on, go to lunch and hook-up electrical ect...to give it an hour,... in all actuality, I know of very few that use the vacuum gauge, they all claim it takes too long. Plus their expensive. You could get by on high temp but I think med & low temp is vital....
 
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Old 03-29-03, 07:55 AM
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Sears

This was of course BEFORE the days of recovery.... even when that first started, they were trying to recover the gas in plastic type bags, this would of course be fractional charges...
 
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